How to chroot ntp in Debian

Here are few simple steps to chroot ntp in debian. Add the following to file /usr/local/sbin/chroot-ntp and execute (alternatively you can download script from bitbucket site here):

#!/bin/bash

/etc/init.d/ntp stop

rootfs=/var/chroot/ntp
mkdir -p $rootfs/{etc,var/lib/ntp,var/log}

mv /etc/ntp.conf $rootfs/etc
ln -s $rootfs/etc/ntp.conf /etc/ntp.conf

if [ -e /var/lib/ntp/ntp.drift ]; then
    mv /var/lib/ntp/ntp.drift $rootfs/var/lib/ntp
fi
ln -s $rootfs/var/lib/ntp/ntp.drift \
    /var/lib/ntp/ntp.drift
chown -R ntp:ntp $rootfs/var/lib/ntp

mv /var/log/ntpstats $rootfs/var/log
ln -s $rootfs/var/log/ntpstats /var/log/ntpstats
chown -R ntp:ntp $rootfs/var/log/ntpstats

sed -e "s,'-g','-4 -i /var/chroot/ntp -g'," \
    /etc/default/ntp > /tmp/x && \
    mv /tmp/x /etc/default/ntp

sed -e "s,restrict -6,#restrict -6," \
    -e "s,restrict ::1,#restrict ::1," \
    /etc/ntp.conf > /tmp/x && \
    mv /tmp/x /etc/ntp.conf

/etc/init.d/ntp start

Verify that ntp uses the chroot (file /etc/default/ntp):

NTPD_OPTS='-4 -i /var/chroot/ntp -g'